on the right turn problem: try hand rolling the plane.
If it tracks straight, then its thrust line and/or rudder offset. (might have cross corrected rudder with aileron and at low speed adverse yaw makes BOTH turn the plane the same way. Nosewheel and rudder should be corrected in that case.)

If it pulls off to one side, check that the mains both turn freely. If they drag, they won't drag evenly. (check that they turn freely anyway... you could have corrected for the drag with the nosewheel...)

Check that the mains are straight. if they have toe-in or toe-out, it can make steering "interresting." Visible toe angle is too much on ANY plane. Chamber angle should be as close to 0 as possible with the model sitting at rest. (thats the vertical alignment component)

check that the fuselage is built straight... a crooked fuselage makes it hard to get anything lined up straight. And then check that the mains are mounted straight on the fuselage. (or that the wires haven't bent backward... See wheel alignment above.)

A fix for wheels that wobble on the axle: drill them out and insert brass tube bushings. The tube should be a close slip fit on the axle, and a tight fit in the drilled wheel hub. You can use multiple "telescoping" tubes.